Electrophoresis Chip and Electrophoresis Unit Having the Same

ABSTRACT

In order to provide a high-performance electrophoresis chip and an electrophoresis unit having the same that can restrain the diffusion of sample at an intersection between the electrophoresis groove and the sample introduction groove and prevent decrease in contrast and decrease in resolution, an electrophoresis chip is provided with a sample introduction groove, an electrophoresis groove, and a through hole. The sample introduction groove, the electrophoresis groove, and the through hole are formed on different substrates. In the electrophoresis chip, by combining the substrates, the sample introduction groove and the electrophoresis groove are located in different planes.

TECHNICAL FIELD

The present invention relates to an electrophoresis chip and anelectrophoresis unit having the same for analyzing blood components,protein, and nucleic acids.

BACKGROUND ART

Conventionally, electrophoresis units provided with electrophoresischips have been used to precisely analyze protein, nucleic acids and soon.

The electrophoresis chips of electrophoresis units generally have anelectrophoresis groove and a sample introduction groove on one substrate(refer to Patent Document 1).

When samples are analyzed with electrophoresis chips of this type, anelectrophoresis liquid is introduced into electrophoresis grooves, and asample is introduced into the sample introduction groove, for example.Then, a voltage is applied between ends of the sample introductiongroove to move the sample to an intersection with the electrophoresisgroove by electrophoresis, and then another voltage is applied betweenends of the electrophoresis groove to move the sample through theelectrophoresis groove.

Because each component contained in the sample that is moving throughthe electrophoresis groove has different electrophoretic speedsaccording to its size, ion composition, and so on, each of thecomponents is separated from one another in the electrophoresis groove.This makes it possible to detect and analyze separated desiredcomponents only by introducing small quantities of the sample.

Patent Document 1: Unexamined Patent Publication H08-178897 (publishedon Jul. 12, 1996)

DISCLOSURE OF INVENTION

The conventional electrophoresis chip has, however, problems describedhereinafter.

Specifically, in the electrophoresis chip disclosed in theabove-mentioned patent publication, the electrophoresis groove and thesample introduction groove simply intersect each other at anintersection, i.e., there are no means to block the travel of the liquidthat reciprocates between each groove. Accordingly, when the sample iselectrophoresed in the electrophoresis groove after it is moved throughthe sample introduction groove to the intersection, the sample might tobe diffused from the intersection in every direction. The diffusion ofthe sample will be a cause of decreasing contrast and resolution at thesample analysis.

It is an object of the present invention to provide an electrophoresischip and an electrophoresis unit having the same, where it is possibleto prevent the decrease contrast and resolution by reducing thediffusion of the sample at the intersection between the sampleintroduction groove and the electrophoresis groove.

An electrophoresis chip according to a first aspect of the inventionelectrophoreses a sample to be analyzed. The electrophoresis chipcomprises a first sample introduction groove, a second sampleintroduction groove, a first electrophoresis groove, a secondelectrophoresis groove, and a through hole. The sample is introducedinto the first sample introduction groove. The sample is thereafterintroduced into the second sample introduction groove. The second sampleintroduction groove is formed in a plane different from a plane in whichthe first sample introduction groove is formed. The firstelectrophoresis groove is located along a direction that intersects withat least one of the first sample introduction groove and the secondsample introduction groove. The second electrophoresis groove is locatedalong a direction that intersects with at least one of the first sampleintroduction groove and the second sample introduction groove. Thesecond electrophoresis groove is formed in a plane different from aplane in which the first electrophoresis groove is formed. The throughhole connects the first sample introduction groove with the secondsample introduction groove. The through hole connects the firstelectrophoresis groove and the second electrophoresis groove with eachother.

In this aspect, each of the electrophoresis groove and the sampleintroduction groove is divided into halves. One of the sampleintroduction grooves and the other are formed in different planes, andone of the electrophoresis grooves and the other are formed in differentplanes. The first sample introduction groove and the second sampleintroduction groove that are formed in the different planes, and thefirst electrophoresis groove and the second electrophoresis groove thatare formed in the different planes are connected via one through hole.In other words, the first sample introduction groove, the second sampleintroduction groove, the first electrophoresis groove, and the secondelectrophoresis groove are communicated with each other via one throughhole.

For example, when a voltage is applied to two ends of the first sampleintroduction groove and the second sample introduction groove that arenot connected with each other (both ends if the first and second sampleintroduction grooves are considered to be one groove) and a sample to beanalyzed is introduced into one end, the sample is introduced to theother end via the through hole. Next, when a voltage is applied to twoends of the first electrophoresis groove and the second electrophoresisgroove that are not connected with each other (both ends if the firstand the second electrophoresis grooves are considered to be one groove),the sample introduced in the through hole, which connects the firstsample introduction groove with the second sample introduction grooveand connects the first electrophoresis groove with the secondelectrophoresis groove, is separated by electrophoresis.

As described above, since the separation and analysis are performed byelectrophoresis by introducing the sample into the common through holethat connects the first and second sample introduction grooves with eachother and the first and second electrophoresis grooves with each other,it is possible to reduce the amount of diffusion of the sampleintroduced into the through hole into the electrophoresis liquid,compared to the conventional electrophoresis chip in which the sampleintroduction groove and the electrophoresis groove are simply intersectwith each other in a single plane. The reason is that a rate of thesample in contact with the electrophoresis liquid to the whole sample isreduced by extending the through hole. As a result, it is possible toprevent problems from occurring such as decrease in contrast or decreasein resolution when the sample separated by electrophoresis is analyzed.

Furthermore, since the separation process can be performed byelectrophoresis using the sample introduced into the through hole, it ispossible to perform the separation and analysis while ensuring a morestable amount of the sample at every test, compared to the conventionalelectrophoresis chip in which the sample introduction groove and theelectrophoresis groove simply intersect with each other in one plane.

An electrophoresis chip according to a second aspect of the presentinvention is the electrophoresis chip according to the first aspect,wherein the through hole is configured to have a cross section where alength in a direction in which the sample is separated byelectrophoresis is shorter than a length in a direction in which thesample is introduced.

In this aspect, a cross-sectional shape of the common through holeconnecting the first and second sample introduction grooves and thefirst and second electrophoresis grooves is defined.

Specifically, the cross section of the through hole is configured suchthat the through hole has a direction in which the sample is introducedand a separating direction by electrophoresis, and a length in theseparating direction by electrophoresis in a cross-sectional shape isshorter than a length of the direction in which the sample is introducedin a cross-sectional shape.

As a result, it is possible to reduce the diffusion of the sample thatis introduced into the through hole into directions other than theseparation direction during electrophoresis, thereby making it possibleto more precisely analyze components.

An electrophoresis chip according to a third aspect of the invention isthe electrophoresis chip according to the first or second aspect,wherein the first sample introduction groove and the firstelectrophoresis groove are formed on one substrate.

In this aspect, a positional relationship between the first sampleintroduction groove and the first electrophoresis groove is defined.

Since the first sample introduction groove and the first electrophoresisgroove are formed on one substrate as described above, it is possible tominimize the number of substrates, thereby simplifying the structure andcutting down on costs.

An electrophoresis chip according to a fourth aspect of the invention isthe electrophoresis chip according to any of the first through thirdaspects, wherein the second sample introduction groove and the secondelectrophoresis groove are formed on one substrate.

In this aspect, a positional relationship between the second sampleintroduction groove and the second electrophoresis groove is defined.

Since the second sample introduction groove and the secondelectrophoresis groove are formed on one substrate as described above,it is possible to minimize the number of substrates, thereby simplifyingthe structure and cutting down on costs. Especially, since the secondsample introduction groove and the second electrophoresis groove areformed on another substrate as well as forming the first sampleintroduction groove and first electrophoresis groove on one substrate,it is possible to configure an electrophoresis chip according to thepresent invention by three substrates that are formed by combining themwith the substrate in which the through hole is formed.

An electrophoresis chip according to a fifth aspect of the invention isthe electrophoresis chip according to the third or fourth aspect,wherein a pretreatment unit is formed on the substrate for pretreatingthe sample.

In this aspect, the pretreatment unit that pretreats the sample isformed on the substrate on which the sample introduction groove isformed.

Accordingly, since the pretreatment unit can be formed without concernfor a portion where the electrophoresis groove is formed, it is possibleto downsize the electrophoresis chip and obtain integratedelectrophoresis chips compared to a case in which pretreatment unit isformed on an electrophoresis chip that has the electrophoresis grooveand the sample introduction groove on one substrate.

An electrophoresis chip according to a sixth aspect of the inventionapplies a voltage between ends of a groove into which an electrophoresisliquid is introduced to electrophorese a sample to be analyzed. Theelectrophoresis chip comprises a sample introduction groove and anelectrophoresis groove. Into the sample introduction groove, the sampleto be analyzed is introduced. The electrophoresis groove is locatedalong a direction that intersects with the sample introduction groove,and has both ends to which a voltage is applied to separate the sampleby electrophoresis. The sample introduction groove and theelectrophoresis groove are formed in different planes.

In this aspect, the sample introduction groove and the electrophoresisgroove are located in different planes three-dimensionally.

The conventional electrophoresis chip is typically configured such thatthe sample introduction groove and the electrophoresis groove are formedin one plane and simply intersect with each other. Accordingly, it islikely that the sample introduced into the sample introduction grooveand the electrophoresis liquid within the electrophoresis groove aremixed and the sample is diffused. Furthermore, in the case that thesample to be analyzed is pretreated in advance of performing theanalysis with the electrophoresis chip, if the pretreatment unit isformed on the same substrate to obtain an integrated chip, the chipcannot avoid its upsizing.

Therefore, in the electrophoresis chip according to the presentinvention, the sample introduction groove and the electrophoresis grooveare placed in different planes, not in the same plane.

Accordingly, it is possible to reduce the diffusion of sample at theintersection between the sample introduction groove and theelectrophoresis groove, compared to a structure in which the sampleintroduction groove and the electrophoresis groove simply intersect witheach other in one plane. Furthermore, since the sample introductiongroove and the electrophoresis groove can be formed on differentsubstrates, even if the pretreatment unit is formed on one substrate forintegration, it is possible to form the pretreatment unit at anypositions on the substrate on which the sample introduction groove isformed except for a position where the sample introduction groove isformed. As a result, since it is possible to form the pretreatment unitwithout concern for the portion where the electrophoresis groove isformed, it is possible to achieve a size reduction of theelectrophoresis chip, compared to the electrophoresis chip having astructure in which both grooves are formed in one plane.

An electrophoresis chip according to a seventh aspect of the inventionis the electrophoresis chip according to the sixth aspect furthercomprises a through hole located at an intersection between theelectrophoresis groove and the sample introduction groove in plan view,for communicating the electrophoresis groove with the sampleintroduction groove.

In this aspect, the sample introduction groove and the electrophoresisgroove located in different planes three-dimensionally are communicatedvia the through hole communicating both grooves with each other.

More specifically, when the analysis is performed with theelectrophoresis chip according to the present invention, the sampleintroduced into one end of the sample introduction groove is moved to aconnection portion with the through hole communicating with theelectrophoresis groove by applying a voltage between ends of the sampleintroduction groove. Then, while the sample is distributed at theconnection portion between the through hole and the electrophoresisgroove, a voltage is applied between ends of the electrophoresis groove.Accordingly, components contained in the sample are moved through theelectrophoresis groove at different speeds depending on different sizesor ion compositions, so that the components can be separated in theelectrophoresis groove. By detecting and analyzing the separatedcomponents, it is possible to perform a precise analysis easily by justintroducing small amounts of sample.

In the electrophoresis chip according to the present invention, thesample introduction groove and the electrophoresis groove arecommunicated with each other via the through hole. Accordingly, it ispossible to reduce the diffusion of sample at the intersection betweenthe sample introduction groove and the electrophoresis groove moreeffectively.

It is preferable that the through hole has a minimum length to preventthe diffusion of sample because it is necessary for the sample that hasbeen moved through the sample introduction groove to move toward theelectrophoresis groove at the through hole at a pre-stage when a voltageis applied between ends of the electrophoresis groove. Alternatively, itis preferable that the sample introduction groove is located above theelectrophoresis groove. In this structure, it is possible to move thesample that has been moved to the connection portion of the sampleintroduction groove with the through hole toward the electrophoresisgroove by gravity or capillary force.

An electrophoresis chip according to an eighth aspect of the inventionis the electrophoresis chip according to the sixth or seventh aspectfurther comprising a valve mechanism in the through hole for preventinga mixture of an electrophoresis liquid introduced into theelectrophoresis groove and a sample introduced into the sampleintroduction groove.

In this aspect, the valve mechanism, which is located at theintersection between the sample introduction groove and theelectrophoresis groove, e.g., the through hole communicating the sampleintroduction groove with the electrophoresis groove, can prevent thediffusion of sample due to the mixture of the sample and theelectrophoresis liquid.

In a case that the sample introduction groove and the electrophoresisgroove that are placed in different planes three-dimensionally simplyintersect with each other, the sample that is moved through the sampleintroduction groove to the intersection by electrical injection may bediffused from the sample introduction groove in every direction of theelectrophoresis grooves and the sample introduction grooves at apre-stage when a voltage is applied between ends of the electrophoresisgroove.

Therefore, in the electrophoresis chip according to the presentinvention, the valve mechanism is provided in the through hole, e.g., atthe intersection between both grooves, and the valve mechanism ischanged into an open state immediately before applying a voltage betweenends of the electrophoresis groove. As a result, it is possible toprevent the diffusion of sample, thereby preventing the generation ofpoor contrast in the electrophoretic pattern or the decrease inresolution.

An electrophoresis chip according to a ninth aspect of the inventionapplies a voltage between ends of a groove into which an electrophoresisliquid is introduced to electrophorese a sample to be analyzed. Theelectrophoresis chip comprises a sample introduction groove, anelectrophoresis groove, and a valve mechanism. The sample to be analyzedis introduced into the sample introduction groove. The electrophoresisgroove is located along a direction that intersects with the sampleintroduction groove, and has both ends to which a voltage is applied toseparate the sample by electrophoresis. The valve mechanism is locatedat an intersection between the electrophoresis groove and the sampleintroduction groove, and prevents a mixture of the electrophoresisliquid and the sample.

In this aspect, the valve mechanism is provided that prevents a mixtureof the electrophoresis liquid and the sample at the intersection betweenthe sample introduction groove and the electrophoresis groove.

The conventional electrophoresis chip is configured such that the sampleintroduction groove and the electrophoresis groove that are formed in asingle plane simply intersect with each other. Accordingly, the sampleintroduced into the sample introduction groove might be diffused inevery direction at the intersection between the sample introductiongroove and the electrophoresis groove. It is quite likely that thesample is diffused when an aqueous solution is used as anelectrophoresis liquid, and the diffusion may cause problems such asdecrease in contrast of the electrophoretic pattern or decrease inresolution.

Therefore, in the electrophoresis chip according to the presentinvention, the valve mechanism is provided so as to partition the sampleintroduction groove from the electrophoresis groove, so that the sampleis prevented from being diffused in advance of the start ofelectrophoresis. Consequently, it is possible to prevent the diffusionof sample by changing the valve mechanism to an open state immediatelybefore applying a voltage between ends of the electrophoresis groove. Asa result, it is possible to prevent the generation of poor contrast inthe electrophoretic pattern or the decrease in resolution due to thediffusion of sample.

An electrophoresis chip according to a tenth aspect of the invention isthe electrophoresis chip according to the eighth or ninth aspect,wherein the valve mechanism can be changed into an open state by usingany of mechanical, electrical, and optical means.

In this aspect, it is possible to change the valve mechanism to an openstate mechanically, electrically, or optically at timing when a voltageis applied between ends of the electrophoresis groove. As a result, itis possible to prevent the generation of poor contrast in theelectrophoretic pattern and the decrease in resolution due to themixture of the sample and the electrophoresis liquid.

An electrophoresis chip according to an eleventh aspect of the inventionis the electrophoresis chip according to the tenth aspect, wherein thevalve mechanism can be opened and closed repeatedly.

In this aspect, since the valve mechanism can be opened and closed bythe mechanical, electrical, or optical means repeatedly, it is possibleto use the electrophoresis chip repeatedly. As a result, even if theelectrophoresis chip is applied to an expensive one, it can cut down oncosts by using it repeatedly.

An electrophoresis chip according to a twelfth aspect of the inventionis the electrophoresis chip according to the tenth aspect, wherein thevalve mechanism includes a membrane that can be opened by light.

In this aspect, by applying laser to the light opening membrane todestroy it at timing when a voltage is applied between ends of theelectrophoresis groove, it is possible to change the valve mechanism toan open state easily. As a result, it is possible to prevent thegeneration of poor contrast in the electrophoretic pattern or thedecrease in resolution due to the diffusion of sample.

If the light opening membrane is employed as a valve mechanism, it ispreferable that the membrane is mainly applied to disposableelectrophoresis chips because it is difficult to change the membraneback to a closed state after it is changed to an open state by applyingthe laser.

An electrophoresis chip according to a thirteenth aspect of theinvention is the electrophoresis chip according to any of the firstthrough twelfth aspects, wherein the electrophoresis liquid is anaqueous solution.

Typically, if an aqueous solution is employed as an electrophoresisliquid, the sample and the electrophoresis liquid are likely to be mixedwith each other at the intersection between the sample introductiongroove and the electrophoresis groove, and the sample is highly likelyto be diffused.

However, since the electrophoresis chip according to the presentinvention is configured such that the sample is unlikely to be diffusedinto the electrophoresis liquid at the intersection between the sampleintroduction groove and the electrophoresis groove, it is possible toprevent a mixture of the electrophoresis liquid and the sample. As aresult, even if the aqueous solution is employed as an electrophoresisliquid, it is possible to obtain an electrophoresis chip having highcontrast and high resolution.

An electrophoresis chip according to a fourteenth aspect of theinvention is the electrophoresis chip according to any of the sixth tothirteenth aspects further comprises a first substrate on which theelectrophoresis groove is formed, and a second substrate on which thesample introduction groove is formed.

In this aspect, the electrophoresis groove and the sample introductiongroove are formed on different substrates. Accordingly, it is possibleto easily realize an electrophoresis chip having a three-dimensionalstructure in which the sample introduction groove and theelectrophoresis groove are formed in different planes by combining thesesubstrates.

An electrophoresis chip according to a fifteenth aspect of the inventionis the electrophoresis chip according to the fourteenth aspect, whereinthe first substrate and the second substrate are oriented parallel toeach other.

In this aspect, since the first substrate on which the electrophoresisgroove is formed and the second substrate on which the sampleintroduction groove is formed are placed parallel to each other, it ispossible to realize a thin electrophoresis chip having athree-dimensional structure in which the sample introduction groove andthe electrophoresis groove are formed in different planes.

An electrophoresis chip according to the sixteenth aspect of theinvention is the electrophoresis chip according to the fourteenth orfifteenth aspect, wherein a pretreatment unit is formed on the secondsubstrate for pretreating the sample.

In this aspect, the pretreatment unit that pretreats the sample isformed on the second substrate on which the sample introduction grooveis formed. Consequently, since the pretreatment unit can be formedwithout concern for a portion where the electrophoresis groove isformed, it is possible to downsize electrophoresis chips to obtainintegrated electrophoresis chips, compared to a case in which apretreatment unit is formed on one substrate of the electrophoresis chipon which the electrophoresis groove and the sample introduction grooveare formed.

An electrophoresis chip according to a seventeenth aspect of theinvention is the electrophoresis chip according to the fifth or thesixteenth aspect, wherein the pretreatment unit performs a process ofdestroying erythrocytes of blood to take out hemoglobin.

In this aspect, as a pretreatment, the process is performed ofdestroying erythrocytes contained in blood as a stage in advance ofmeasuring hemoglobin A1c. Accordingly, it is possible to take outhemoglobin A1c to measure the amount of hemoglobin A1c just byintroducing the blood into one chip to separate components byelectrophoresis.

An electrophoresis unit according to an eighteenth aspect of theinvention comprises the electrophoresis chip set forth in any of thefirst through seventeenth aspects, a detection unit, and an analysisunit. The detection unit detects components contained in the sample thatis separated in the electrophoresis groove. The analysis unit analyzesthe components detected by the detection unit.

In this aspect, since the electrophoresis chip that makes it possible torealize more downsizing and integration is provided, the electrophoresisunit can be downsized, too. If the electrophoresis chip with the valvemechanism is provided, even if the aqueous solution is employed as anelectrophoresis liquid, for example, it is possible to prevent a mixtureof the sample and the electrophoresis liquid, thereby obtainingelectrophoresis units having no poor contrast and having a highresolution.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a schematic structure of theelectrophoresis unit having the electrophoresis chip according to oneembodiment of the present invention.

FIG. 2 is a perspective view of a structure of the electrophoresis chipshown in FIG. 1.

FIG. 3 is an exploded perspective view in which the substrates of theelectrophoresis chip in FIG. 2 are shown separated from one another.

FIG. 4 is a perspective view of a valve mechanism of the electrophoresischip in FIG. 2.

FIG. 5 is a perspective view of a structure of the electrophoresis chipaccording to another embodiment of the present invention.

FIG. 6 is a perspective view of the individual substrate constitutingthe electrophoresis chip in FIG. 5.

FIG. 7 is a perspective view of another of the individual substratesconstituting the electrophoresis chip in FIG. 5.

FIG. 8 is a perspective view of still another of the individualsubstrates constituting the electrophoresis chip in FIG. 5.

FIG. 9 is an enlarged view of the intersection between the sampleintroduction groove and the electrophoresis groove of theelectrophoresis chip in FIG. 5.

FIG. 10 is a perspective view of a structure of the electrophoresis chipaccording to a still further embodiment of the present invention.

FIG. 11 is an exploded perspective view of the various substrates thatconstitute the electrophoresis chip in FIG. 10.

FIG. 12 is an enlarged view of a through hole formed in theelectrophoresis chip in FIG. 10.

FIG. 13 is an explanatory view of a process flow using theelectrophoresis chip in FIG. 10.

EXPLANATIONS OF LETTERS OR NUMERALS

-   10 electrophoresis chip-   10 a substrate (second substrate)-   10 b substrate-   10 c substrate (first substrate)-   11 sample introduction groove-   11 a, 11 b openings-   12 electrophoresis groove-   12 a, 12 b openings-   13 through hole-   14 valve mechanism-   14 a light opening membrane-   14 b irradiation unit-   20 pretreatment unit-   21 mix diffusion dilution unit-   22 a pretreatment liquid reservoir-   22 b electrophoresis liquid reservoir-   23 introduction hole-   24 sample-before-pretreatment introduction groove-   25 pretreatment liquid introduction groove-   26 a to 26 d air holes-   27 detection unit-   30 detection unit-   31 light receiving unit-   32 laser irradiating unit-   40 analysis unit-   50 electrophoresis unit-   60 electrophoresis chip-   60 a substrate (second substrate)-   60 b substrate-   60 c substrate (first substrate)-   61 sample introduction groove-   62 electrophoresis groove-   62 a, 62 b openings-   63 through hole-   70 electrophoresis chip-   70 a substrate-   70 b substrate-   70 c substrate-   71 a first sample introduction groove-   71 b second sample introduction groove-   72 a first electrophoresis groove-   72 b second electrophoresis groove-   73 through hole-   74 a, 74 b openings-   75 a, 75 b openings

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

A description is now provided for an electrophoresis chip 10 and anelectrophoresis unit 50 having the same according to one embodiment ofthe present invention with reference to FIGS. 1 through 4.

[Whole Structure of the Electrophoresis Unit]

The electrophoresis unit 50 according to the present embodiment is ananalysis device that is provided with the electrophoresis chip 10according to the present invention to precisely analyze blood, protein,nucleic acids and so on in samples.

The electrophoresis unit 50 is provided with the electrophoresis chip10, a detection unit 30, and an analysis unit 40, as shown in FIG. 1.

The electrophoresis chip 10 is provided with a sample introductiongroove 11, an electrophoresis groove 12, and a through hole 13 as shownin FIG. 2. The electrophoresis chip 10 separates each componentcontained in the sample by applying a voltage between ends of the sampleintroduction groove 11 to move the sample through the sampleintroduction groove 11 by electrophoresis.

It should be noted that the structure of the electrophoresis chip 10will be described in greater detail below.

The detection unit 30 is provided with a light receiving unit 31 and alaser irradiating unit 32. The light receiving unit 31 is located on anopposite side of the laser irradiating unit 32 across theelectrophoresis chip 10, and detects a transmitted light from laserlight applied to the sample in the electrophoresis groove 12. The laserirradiating unit 32 applies the laser light to each separated componentin the electrophoresis groove 12.

The analysis unit 40 includes an A/D converter, a CPU and among otherthings (not illustrated) therein. The A/D converter coverts opticalsignals of the transmitted light, which are detected at the lightreceiving unit 31 and amplified after the detection, into digitalsignals. The CPU receives the digital signals, which are converted fromthe optical signals by the A/D converter, and distributions or the likecorresponding to the electrophoresis groove 12 are displayed on amonitor as an analysis output of the components being analyzed.

[Structure of the Electrophoresis Chip]

The electrophoresis chip 10 according to the present embodiment isprovided with the sample introduction groove 11, the electrophoresisgroove 12 and the through hole 13, as mentioned above, which are locatedeach in different planes three-dimensionally (see FIG. 2).

As shown in FIG. 3, the sample introduction groove 11, theelectrophoresis groove 12, and the through hole 13 are formed ondifferent substrates 10 a to 10 c, and the substrates 10 a to 10 c arecombined to locate the sample introduction groove 11 and theelectrophoresis groove 12 in different planes three-dimensionally.

The substrate (second substrate) 10 a is formed with the sampleintroduction groove 11, openings 11 a and 11 b, and openings 12 a and 12b. It should be noted that the openings 11 a, 11 b, 12 a, and 12 b areformed by etching the substrate 10 a, for example, as in the case withthe sample introduction groove 11.

The substrate 10 b is formed with the through hole 13 and the openings12 a and 12 b.

The substrate (a first substrate) 10 c is formed with theelectrophoresis groove 12 by etching, for example, as in the case withthe sample introduction groove 11 on the substrate 10 a.

The sample introduction groove 11 is formed on a contact surface of thesubstrate 10 a with the substrate 10 b by etching, for example. Bycombining the substrate 10 a and the substrate 10 b together, acapillary is defined between a portion corresponding to the sampleintroductions groove 11 and the substrate 10 b. The sample introductiongroove 11 is connected with the openings 11 a and 11 b formed on thesubstrate 10 a. A sample to be analyzed is introduced by pressure orelectrical injection into the openings 11 a and 11 b. If the electricalinjection is employed, electrodes (not illustrated) are connected toboth ends of the sample introduction groove 11 to apply a voltagethereto.

The electrophoresis groove 12 is formed on a contact surface of thesubstrate 10 c with the substrate 10 b by etching, for example, as inthe case of the sample introduction groove 11. The groove 12 isconnected to the openings 12 a and 12 b. By combining the substrate 10 cand the substrate 10 b together, a capillary is defined between aportion corresponding to the electrophoresis groove 12 and the substrate10 b. The openings 12 a and 12 b are formed on the substrate 10 a and 10b, respectively, and electrodes (not illustrated) are connected to bothends of them to apply a voltage thereto.

The through hole 13 is a hole penetrating through the substrate 10 b ina perpendicular direction to communicate the sample introduction groove11 with the electrophoresis groove 12. Moreover, the through hole 13 isprovided with a valve mechanism 14 to prevent a mixture of the sample inthe sample introduction groove 11 and the electrophoresis liquid in theelectrophoresis groove 12, and the diffusion of the sample (refer toFIG. 4).

As shown in FIG. 4, the valve mechanism 14 includes a light openingmembrane 14 a positioned to partition the sample introduction groove 11from the electrophoresis groove 12, and an irradiation unit 14 b toapply laser light to the light opening membrane 14 a. In the valvemechanism 14, the light opening membrane 14 a contains dye, and theirradiation unit 14 b irradiates the light opening membrane 14 a withthe laser light in order to change to an open state. Then, the dyecontained in the light opening membrane 14 a absorbs heat of the laserlight and the light opening membrane 14 a is destroyed, thereby thevalve mechanism 14 can be changed to an open state in which the sampleintroduction groove 11 and the electrophoresis groove 12 communicatewith each other. In place of the irradiation unit 14 b, the laserirradiating unit 32 of the detection unit 30 may be used.

<Analysis by the Electrophoresis Unit>

In the electrophoresis unit 50 according to the present embodiment,blood components, protein or the like are analyzed by the followingprocedure.

First, the electrophoresis chip 10, in which the sample introductiongroove 11 and the electrophoresis groove 12 are filled with theelectrophoresis liquid, is set onto a rest base of the electrophoresisunit 50, and a sample to be analyzed is introduced into the opening 11 aor 11 b of the sample introduction groove 11 by pressure or electricalinjection.

Next, the electrodes are connected to the openings 11 a and 11 b atopposite ends of the sample introduction groove 11, and then a voltageis applied to the ends to move the sample to the intersection betweenthe sample introduction groove 11 and the electrophoresis groove 12. Atthis time, the laser light is applied by the irradiation unit 14 b tothe light opening membrane 14 a of the valve mechanism 14 installed inthe through hole 13 so that the light opening membrane 14 a is destroyedto communicate the sample introduction groove 11 with theelectrophoresis groove 12. Accordingly, the sample can be moved from thethrough hole 13 toward the electrophoresis groove 12. After that, theelectrodes are connected to the openings 12 a and 12 b at opposite endsof the electrophoresis groove 12, and a voltage is applied to the endsof the electrophoresis groove 12. As a result, the components containedin the sample, which is moved to the intersection between the sampleintroduction groove 11 and the electrophoresis groove 12, can beseparated in the electrophoresis groove 12.

After applying the voltage to the ends of the electrophoresis groove 12for the predetermined time to separate the components contained in thesample, the laser light is applied to the separated components by thelaser irradiating unit 32 of the detection unit 30. The applied laserlight transmits through the components and is detected by the lightreceiving unit 31. Then, the optical signals detected by the lightreceiving unit 31 are sent to the analysis unit 40.

The analysis unit 40 converts the optical signals sent from the lightreceiving unit 31 into digital signals, and the built-in CPU displaysanalysis outputs such as a component distribution based on the digitalsignals on the monitor.

In the electrophoresis unit 50 according to the present embodiment, withthe above-described procedure, the sample introduced into the sampleintroduction groove 11 can be separated into the components and thecomponents can be analyzed individually.

[Features]

(1)

In the electrophoresis chip 10 according to the present embodiment, thesample introduction groove 11 and the electrophoresis groove 12 areplaced in the different planes (on the substrates 10 a and 10 c)three-dimensionally.

According to an analysis using the electrophoresis chip 10 as in thepresent embodiment, first, the sample, which is introduced into thesample introduction groove 11 by using a method such that a voltage isapplied to opposite ends of the sample introduction groove 11, is movedto the intersection with the electrophoresis groove 12. At this stage,at the intersection between the sample introduction groove 11 and theelectrophoresis groove 12, the sample and the electrophoresis liquiddisposed in the electrophoresis groove 12 might be mixed so that thesample could be diffused from the intersection in every direction, inadvance of applying a voltage to the ends of the electrophoresis groove12. The diffusion of the sample in advance of the start ofelectrophoresis might cause problems such as decreasing contrast in theelectrophoretic pattern of the sample after the analysis or decreasingresolution.

Therefore, in the electrophoresis chip 10 according to the presentembodiment, the sample introduction groove 11 and the electrophoresisgroove 12 are placed in different planes in order to suppress thediffusion of the sample between the sample introduction groove 11 andthe electrophoresis groove 12 before the start of electrophoresis.

Accordingly, it is possible to prevent the sample from being diffused ata pre-stage when starting the electrophoresis by applying the voltagebetween ends of the electrophoresis groove 12, compared to theconventional structure in which the sample introduction groove 11 andthe electrophoresis groove 12 simply intersect with each other in oneplane. As a result, it is possible to obtain the high-performanceelectrophoresis chip 10 by restraining the problems from occurring suchas the generation of poor contrast in the electrophoretic pattern andthe decrease in resolution due to the diffusion of the sample.

Furthermore, it is possible to form the sample introduction groove 11and the electrophoresis groove 12 on the separate substrates 10 a and 10c respectively by placing the sample introduction groove 11 and theelectrophoresis groove 12 in the different planes three-dimensionally.As a result, even if the electrophoresis chip 10 is configured to havean integrated pretreatment unit formed on one substrate (the substrate10 a) on which only the sample introduction groove 11 is formed, forexample, it is possible to prevent the chip from being enlarged.

(2)

The electrophoresis chip 10 according to the present embodiment isprovided with the through hole 13 that communicates the sampleintroduction groove 11 with the electrophoresis groove 12.

Accordingly, it is possible to restrain the diffusion of sample moreeffectively because of the communication via the through hole 13compared to a structure in which the sample introduction groove 11 andthe electrophoresis groove 12 directly intersect with each other. As aresult, it is possible to prevent problems from occurring such as thepoor contrast in the electrophoretic pattern or the decrease inresolution due to the diffusion of sample.

(3)

The electrophoresis chip 10 according to the present embodiment isprovided with the valve mechanism 14 in the through hole 13 formed atthe intersection between the sample introduction groove 11 and theelectrophoresis groove 12 to prevent a mixture of the sample in thesample introduction groove 11 and the electrophoresis liquid in theelectrophoresis groove 12.

Accordingly, it is possible to prevent the sample from being diffused atthe pre-stage when a voltage is applied between ends of the sampleintroduction groove 11 to start electrophoresis. As a result, it ispossible to obtain the high-performance electrophoresis chip 10 byresolving troubles such as poor contrast in the electrophoretic patternor a decrease in resolution due to the diffusion of the sample.

(4)

In the electrophoresis chip 10 according to the present embodiment, as ameans to change the valve mechanism 14 to an open state, the lightopening membrane 14 a and the irradiation unit 14 b to apply laser lightare used.

Since optical means are used such as the light opening membrane 14 a andthe irradiation unit 14 b to apply laser light, it is possible to changethe valve mechanism 14 to an open state by applying the laser light fromthe irradiation unit 14 b to the light opening membrane 14 a in timingimmediately before applying a voltage between ends of theelectrophoresis groove 12. As a result, it is possible to prevent themixture of the sample and the electrophoresis liquid and the diffusionof sample at a stage before the start of electrophoresis.

Furthermore, since the light opening membrane 14 a is used as a valve topartition the sample introduction groove 11 off the electrophoresisgroove 12, it is possible to change the valve mechanism 14 to an openstate easily just by applying the laser light.

(5)

In the electrophoresis chip 10 according to the present embodiment, thesample introduction groove 11 and the electrophoresis groove 12 areformed on the separate substrates 10 a and 10 c, respectively.

Accordingly, it is possible to realize the electrophoresis chip 10having a three-dimensional structure.

(6)

The electrophoresis unit 50 according to the present embodiment isprovided, as described above, with the electrophoresis chip 10, thedetection unit 30 to detect the separated components in theelectrophoresis chip 10, and the analysis unit 40 to analyze thecomponents detected by the detection unit 30.

Accordingly, it is possible to obtain all effects that are obtained bythe electrophoresis chip 10.

Embodiment 2

A description is provided for an electrophoresis chip and anelectrophoresis unit having the same according to the present inventionwith reference to FIGS. 5 through 9. It should be noted that componentshaving the same or similar function to those described in Embodiment 1will be identified by the same reference numerals for convenience ofexplanation, and a duplicate explanation will be omitted.

The electrophoresis chip 60 according to the present embodiment isdifferent from the electrophoresis chip 10 according to Embodiment 1 inthat a pretreatment unit 20 and other components are disposed on asubstrate 60 a as shown in FIG. 5. However, a basic structure of thechip 60 such as a sample introduction groove 61, an electrophoresisgroove 62, and a through hole 63 is similar to that included in thesample introduction groove 11 and so on of the electrophoresis chip 10.

An electrophoresis chip 60 according to the present embodiment is athree-layered chip having a structure of laminating three substrates 60a to 60 c that have the sample introduction groove 61, theelectrophoresis groove 62 and the through hole 63, as shown in FIG. 5,and has the integrated pretreatment unit 20. The pretreatment unit 20performs a pretreatment of destroying erythrocytes by mixing blood and ahemolysis diluent, for example.

The substrate 60 a is mainly formed, as shown in FIG. 6, of the sampleintroduction groove 61, the pretreatment unit 20, and a pretreatmentliquid reservoir 22 a. The pretreatment unit 20 includes a mix diffusiondilution unit 21 that mixes the pretreatment liquid and the sample “a”for diffusion and dilution, an introduction hole 23 to introduce sample“a” (for example, blood) before the pretreatment that is a base ofsample “b” to be analyzed by electrophoresis, asample-before-pretreatment introduction groove 24, and a pretreatmentliquid introduction groove 25. The mix diffusion dilution unit 21 isdisposed between the sample introduction groove 61 and the pretreatmentliquid introduction groove 25, and mixes, diffuses and dilutes thesample “a” to be pretreated before the pretreatment with thepretreatment liquid. The introduction hole 23 is connected to thesample-before-pretreatment introduction groove 24 in the electrophoresischip 60, and introduces the sample “a” that is dropped from thesubstrate 60 a into the electrophoresis chip 60. In thesample-before-pretreatment introduction groove 24, the sample “a”, whichis introduced from the introduction hole 23, is filled up over theintersection with the pretreatment liquid introduction groove 25 up tothe tip. The pretreatment liquid reservoir 22 a is filled with thepretreatment liquid in advance, and the pretreatment liquid is flowninto the pretreatment liquid introduction groove 25 at an appropriate ordesirable time. The pretreatment liquid introduction groove 25 is placedat a position connecting the pretreatment liquid reservoir 22 a and themix diffusion dilution unit 21, and intersects with the above-describedsample-before-pretreatment introduction groove 24.

Since the substrate 60 a has the above-described structure, it ispossible to perform a pretreatment of mixing the sample “a” with thepretreatment liquid to obtain the sample “b”, and send the sample “b”from the mix diffusion dilution unit 21 to the sample introductiongroove 61.

The substrate 60 a is formed with air holes 26 a to 26 c that are openedwhen the sample, the pretreatment liquid, or the electrophoresis liquidis introduced at an appropriate or desirable time, openings 62 a and 62b to which the electrodes are connected to apply a voltage between endsof the electrophoresis groove 62, and a detection unit 27 to detectcomponents of the sample “b” separated in the electrophoresis chip 60 aswell.

The substrate 60 b is formed with the through hole 63 to communicate thesample introduction groove 61 and the electrophoresis groove 62 that areplaced in different planes three-dimensionally, the air hole 26 cpenetrating through the openings 62 a and 62 b and the substrate 60 c,and the detection unit 27. The through hole 63 is provided with thevalve mechanism 14 in the same manner as the through hole 13 inEmbodiment 1, and therefore, explanation is omitted.

The substrate 60 c is formed with the electrophoresis groove 62, theopenings 62 a and 62 b, an electrophoresis liquid reservoir 22 b, theair hole 26 c, and the detection unit 27. The openings 62 a and 62 b areformed at both ends of the electrophoresis groove 62, and to whichelectrodes are connected to apply a voltage to both the ends of theelectrophoresis groove 62. The electrophoresis liquid reservoir 22 b isfilled with the electrophoresis liquid, and supplies the electrophoresisliquid to the electrophoresis groove 62 at an appropriate or desirabletime when the air hole 26 c is opened. The detection unit 27 detectsseparated components by electrophoresis in the electrophoresis groove 62that is contained in the pretreated sample “b” dropped from the throughhole 63. The following process is similar to that by the electrophoresisunit 50 according to Embodiment 1.

<Analysis by the Electrophoresis Unit>

In the electrophoresis unit including the electrophoresis chip 60according to the present embodiment, processes are performed from thepretreatment of the sample to the analysis in the following procedure.

First, the sample “a” is introduced to fill thesample-before-pretreatment introduction groove 24 from the introductionhole 23. Next, the air holes 26 b and 26 d are opened to send a portionof the sample “a” that is disposed in the sample-before-pretreatmentintroduction groove 24 from the pretreatment liquid reservoir 22 a withthe pretreatment liquid to the mix diffusion dilution unit 21. Thesample that is sent to the mix diffusion dilution unit 21 is mixed withthe pretreatment liquid, and is diffused and diluted. Then, the sample“b” that is obtained by pretreating the sample “a” is introduced intothe sample introduction groove 61 by opening the air hole 26 a.Meanwhile, in the substrate 60 c, the electrophoresis liquid isintroduced into the electrophoresis groove 62 from the electrophoresisliquid reservoir 22 b by opening the air hole 26 c.

When the sample “b” is introduced into the sample introduction groove61, the laser light is applied to the light opening membrane formed atthe through hole 63 shown in FIG. 9 to communicate the sampleintroduction groove 61 with the electrophoresis groove 62, so that thesample “b” to be analyzed by electrophoresis is moved to theelectrophoresis groove 62.

In this state, the electrodes are connected to the openings 62 a and 62b, and a voltage is applied between ends of the electrophoresis groove62 to analyze the components of the sample “b” separated byelectrophoresis. The analysis of the separated components of the sample“b” is performed by detecting them in the detection unit 27.

[Features]

(1)

In the electrophoresis chip 60 according to the present embodiment, thesample introduction groove 61 and the electrophoresis groove 62 areplaced in the different planes three-dimensionally.

Typical conventional electrophoresis chips are configured such that thesample introduction groove and the electrophoresis groove are formed inone plane and intersect each other. In this structure, however, if apretreatment unit that pretreats the sample in advance of analyzingcomponents by electrophoresis is formed on the substrate on which theelectrophoresis chip is formed, an area of the chip will be increased bythe amount of the pretreatment unit formed thereon.

Therefore, in the electrophoresis chip 60 according to the presentembodiment, the sample introduction groove 61 and the electrophoresisgroove 62 are placed in different planes, i.e., on the differentsubstrates 60 a and 60 b to form a three-dimensional structure.

Accordingly, since the pretreatment unit 20 is formed on the substrate60 a on which only the sample introduction groove 61 is formed, it ispossible to restrain upsizing of the chip compared to the conventionalstructure in which the sample introduction groove 61 and theelectrophoresis groove 62 are formed on one substrate. In other words,on the substrate 60 a the electrophoresis groove 62 is not formed, butthe sample introduction groove 61 only is formed. As a result, it ispossible to form the pretreatment unit 20 without concern for apositional relationship with the electrophoresis groove 62, onlyconsidering a position where the sample introduction groove 61 isformed. Consequently, it is possible to obtain the integratedelectrophoresis chip 60 while restraining upsizing of the chip, comparedto the conventional structure in which the sample introduction groove 61and the electrophoresis groove 62 are formed on one substrate.

(2)

The electrophoresis chip 60 according to the present embodiment includesthe pretreatment unit 20 that pretreats the sample in advance ofelectrophoresis.

Accordingly, it is possible to obtain a multifunctional chip byrealizing a structure of the electrophoresis chip 60 in which thepretreatment unit 20 is formed on the substrate 60 a.

Embodiment 3

A description is now provided for an electrophoresis chip according tothe present invention with reference to FIGS. 10 to 13. It should benoted that components having functions to the same as those described inEmbodiments 1 and 2 will be identified by the same reference numerals asthe same ones for convenience of explanation, and the explanation willbe omitted.

An electrophoresis chip 70 according to present embodiment has acommonality with the electrophoresis chip 10 in Embodiment 1 in that thesample introduction groove and the electrophoresis groove are formed onthe three substrates 70 a to 70 c as shown in FIG. 10 and FIG. 11.However, in the electrophoresis chip 70 according to the presentembodiment, it differs from the electrophoresis chip 10 in that thesample introduction groove and the electrophoresis groove are halvedrespectively, i.e., the first sample introduction groove 71 a and thefirst electrophoresis groove 72 a are formed on the substrate 70 a, andthe second sample introduction groove 71 b and the secondelectrophoresis groove 72 b are formed on the substrate 70 c.

In the electrophoresis chip 70 according to present the embodiment, asdescribed above, the first sample introduction groove 71 a and thesecond sample introduction groove 71 b are formed in different planes(on the substrate 70 a and the substrate 70 c) and are connected forcommunication with each other via a through hole 73 at their ends.

Similarly, the first electrophoresis groove 72 a and the secondelectrophoresis groove 72 b are formed in different planes (on thesubstrate 70 c and the substrate 70 a), and are connected with eachother for communication via the through hole 73 at their ends, too.

In summary, the first sample introduction groove 71 a, the second sampleintroduction groove 71 b, the first electrophoresis groove 72 a, and thesecond electrophoresis groove 72 b are connected with each other via thecommon through hole 73 for mutual communication.

The through hole 73 is formed on the substrate 70 b, on which neitherthe groove 71 a, 71 b, 72 a, nor 72 b is formed. The through hole 73 hasa cross section with different lengths according to directions such as adirection in which the samples are introduced along the first and secondsample introduction grooves 71 a and 71 b that are formed on an almoststraight line and a direction in which the sample is separated byelectrophoresis along the first and second electrophoresis grooves 72 aand 72 b that are formed on an almost straight line, as shown in FIG.12. More specifically, the through hole 73 has a cross section ofrectangle, wherein narrow sides of the rectangle is placed along adirection in which the sample is separated by electrophoresis, and widesides of the rectangle are placed along a direction in which the sampleis introduced.

[Features]

(1)

In the electrophoresis chip 70 according to present embodiment, as shownin FIG. 10 and FIG. 11, the first sample introduction groove 71 a andthe second sample introduction groove 71 b are placed in differentplanes (on the substrates 70 a and 70 c). Meanwhile, the firstelectrophoresis groove 72 a and the second electrophoresis groove 72 bare placed in different planes (on the substrates 70 c and 70 a), too.The grooves 71 a, 71 b, 72 a, and 72 b are connected with each other viathe through hole 73 for mutual communication.

Accordingly, since the sample introduced into the first and secondsample introduction grooves 71 a and 71 b is also introduced into thethrough hole 73, it is possible to separate a certain amount of sampleintroduced into the through hole 73 for analysis by applying a voltagebetween ends of the first and second electrophoresis grooves 72 a and 72b after introducing the sample.

Consequently, it is possible to perform the separation and analysis byelectrophoresis by reliably ensuring the sample introduced into thecommon through hole 73. As a result, it is possible to reduce the amountof diffusion into electrophoresis liquid (diffusion ratio) of the sampleintroduced into the through hole 73 and to perform the separation andanalysis by ensuring a stable amount of sample for every analysiscompared to the conventional electrophoresis chip in which the sampleintroduction groove and the electrophoresis groove simply intersect witheach other in one plane.

(2)

In the electrophoresis chip 70 according to the present embodiment, thethrough hole 73 that communicates the grooves 71 a, 71 b, 72 a, and 72 bwith each other has a cross section where a length in a direction inwhich the sample is separated by electrophoresis is shorter than alength in a direction in which the sample is introduced.

Since the through hole 73 is configured to have the cross section withdifferent lengths in the direction in which the sample is separated andin the direction in which the sample is introduced, it is possible tosmoothly move the sample introduced into the through hole 73 in anelectrophoretic direction when the sample is separated byelectrophoresis, not diffusing the sample in other directions. As aresult, a width of the peak to be detected becomes narrow, and a highlyprecise analysis output can be obtained.

(3)

In the electrophoresis chip 70 according to present embodiment, thefirst sample introduction groove 71 a and the first electrophoresisgroove 72 a are formed on the substrate 70 a, and the second sampleintroduction groove 71 b and the second electrophoresis groove 72 b areformed on the substrate 70 c.

Accordingly, the electrophoresis chip 70 according to present embodimentcan be realized having a structure in which the substrate 70 b forforming the through hole 73 is sandwiched as one within the threesubstrates 70 a to 70 c. As a result, it is possible to cut down oncosts by simplifying the structure.

[Experiment 1]

Here, a description will be made on the outcome of the separation andanalysis of samples by electrophoresis with the electrophoresis chip 70according to present embodiment with reference to FIG. 13 (a) throughFIG. 13 (d).

As a sample, a mixture was used that included substances having thefollowing final concentrations: 25.0 mM for mesityl oxide; 12.5 mM fortryptophan, 25.0 mM for vitamin B1 hydrochloride, and 0.1 mM for uricacid-sodium with.

First, as shown in FIG. 13 (a), a water-soluble electrophoresis liquidsuch as phosphate buffer (pH 8.7) was injected by pressure into thegrooves 71 a, 71 b, 72 a, and 72 b of the electrophoresis chip 70.Consequently, as shown in FIG. 13 (b), the grooves 71 a, 71 b, 72 a, and72 b were filled with the electrophoresis liquid.

Next, electrodes are connected to the opening 74 a (refer to FIG. 11)formed at the ends of the first sample introduction groove 71 a and theopening 75 b (refer to FIG. 11) formed at the ends of the second sampleintroduction groove 71 b. Then a voltage of 1.5 kV is applied to theelectrodes, so that the sample introduced into the opening 74 a formedat the end of the first sample introduction groove 71 a was introducedfrom the first sample introduction groove 71 a via the through hole 73into the second sample introduction groove 71 b.

After the introduction of the sample, the voltage was stopped from beingapplied to the first and second sample introduction grooves 71 a and 71b, and a voltage was applied between ends (openings 74 b and 75 a) ofthe first and second electrophoresis grooves 72 a and 72 b to start theseparation and analysis by electrophoresis. The voltage was applied at1.5 kV for 15 minutes.

At the same time as the application of voltage, the detection wasperformed at 280 nm at predetermined detection positions in the secondelectrophoresis groove 72 b formed on the substrate 70 c.

As a result, 4 peaks were detected in the order of vitamin B1hydrochloride, mesityl oxide, tryptophan, and uric acid-sodium.

Different absorption spectrums of different substances that hadconfirmed were used to judge the substances.

Other Embodiments

Although one embodiment of the present invention is described above, thepresent invention is not limited to the embodiment, and various changesmay be made without departing from the scope of the invention.

(A)

In Embodiments 1 and 2, an example was described in which the sampleintroduction groove 11, the electrophoresis groove 12, and the throughhole 13 were formed on different substrates and then the substrates werecombined to form a structure of the electrophoresis chip 10. However,the present invention is not limited to this example.

For example, the sample introduction groove 11 and the through hole 13may be formed on one substrate, and the electrophoresis groove 12 andthe through hole 13 may be formed on one substrate. Alternatively, allof the structures may be formed on one substrate.

(B)

In Embodiment 1, an example was described in which the sampleintroduction groove 11 and the electrophoresis groove 12 were placed indifferent planes three-dimensionally, and the through hole 13 thatcommunicated the sample introduction groove 11 with the electrophoresisgroove 12 was provided with the valve mechanism 14. However, the presentinvention is not limited to this example.

For example, the sample introduction groove 11 and the electrophoresisgroove 12 may be formed in one plane, and the sample introduction groove11 and the electrophoresis groove 12 may be provided with the valvemechanism 14 at their intersection.

In this example, too, it is possible to prevent the electrophoresisliquid and the sample from being mixed at a stage in advance of thestart of electrophoresis by changing the valve mechanism 14 to an openstate immediately before applying a voltage between ends of theelectrophoresis groove 12.

(C)

In Embodiments 1 and 2, an example was used in which the aqueoussolution was used as an electrophoresis liquid. However, the presentinvention is not limited to this example.

For example, a gelatinous electrophoresis liquid may be used.

However, it is preferable to use the aqueous solution as anelectrophoresis liquid in a sense that the present invention can be usedmore effectively because the valve mechanism of the through hole 13 isespecially effective in preventing the diffusion of sample even if theelectrophoresis liquid is the aqueous solution that is likely to bemixed with the sample and to be diffused.

(D)

In Embodiments 1 and 2, an example was described in which the sampleintroduction groove 11, the electrophoresis groove 12 and so on wereformed by etching. However, the present invention is not limited to thisexample.

For example, the sample introduction groove 11 and/or theelectrophoresis groove 12 may be formed by other methods such asmachining. However, it is preferable to form the sample introductiongroove 11, the electrophoresis groove 12 and so on by etching to ensurethe processing accuracy while considering the recent size reduction ofchips.

(E)

In Embodiments 1 and 2, an example was described in which the valvemechanism 14 included the light opening membrane 14 a and theirradiation unit 14 b, and the valve mechanism 14 was opened bydestroying the light opening membrane 14 a by the laser light appliedfrom the irradiation unit 14 b. However, the present invention is notlimited to this example.

For example, the valve such as a membrane may be destroyed by amechanical means or an electrical means for opening, without using theoptical means in Embodiments.

The valve mechanism 14 may employ a structure in which it can not closeitself once it is opened as in Embodiments, or a structure in which itcan be opened and closed repeatedly. However, the valve mechanism thatcan be repeatedly opened and closed is preferable because it can beemployed in a relatively expensive electrophoresis chip to restrainincrease in cost.

(F)

In Embodiments 1 and 2, an example was described in which a crosssection of the through hole 13 that communicates the sample introductiongroove 11 with the electrophoresis groove 12 had a circular shape.However, the present invention is not limited to this example.

For example, a through hole that has a cross-sectional shape ofquadrangle may be used.

(G)

In Embodiment 3, an example was described in which a cross section ofthe through hole 73 was rectangle that communicated the first sampleintroduction groove 71 a with the second sample introduction groove 71b, and the first electrophoresis groove 72 a with the secondelectrophoresis groove 72 b. However, the present invention is notlimited to this example.

For example, a through hole having a cross-sectional shape of circle maybe used, as in the case of the through hole 13 described in Embodiment 1and 2.

However, if the cross section is a rectangle having short sides in adirection in which the sample is separated by electrophoresis as inEmbodiment 3, it is possible to reduce the diffusion of sample duringelectrophoresis as described above, thereby to perform a more highlyprecise detection.

(H)

In Embodiment 3, an example was described in which the sampleintroduction groove 71 a and the electrophoresis groove 72 a were formedin one plane (on the substrate 70 a). However, the present invention isnot limited to this example.

For example, the sample introduction groove 71 a and the electrophoresisgroove 72 a may be formed in different planes.

(I)

In Embodiment 3, an example was described in which the first sampleintroduction groove 71 a and the second sample introduction groove 71 bwere located on an approximately straight line, and the firstelectrophoresis groove 72 a and the second electrophoresis groove 72 bwere located on an approximately straight line. However, the presentinvention is not limited to this example.

For example, the electrophoresis chip 10 shown in FIG. 3 may be usedsuch that a voltage is applied to the opening 11 a and the opening 12 band the sample is introduced into a half of the sample introductiongroove 11 and a half of the electrophoresis groove 12 in the sampleintroduction process, and a voltage is applied to the opening 11 b andthe opening 12 a for separation by electrophoresis in the separationprocess. In other words, one part of the sample introduction groove 11shown in FIG. 3 and one part of the electrophoresis groove 12 may beutilized as sample introduction grooves, and the other part of thesample introduction groove 11 and the other part of the electrophoresisgroove 12 may be used as electrophoresis grooves.

As described above, even if the sample introduction groove andelectrophoresis groove are figured to be bent in the middle, it ispossible to restrain the diffusion of the sample introduced into thethrough hole 13 and perform a separation process with a stable amount ofthe sample introduced into the through hole 13 every time.

(J)

In Embodiment 3, an example was described in which the first and secondsample introduction grooves 71 a and 71 b, the first and secondelectrophoresis grooves 72 a and 72 b and the through hole 73 wereformed on the substrates 70 a to 70 c. However, the present invention isnot limited to this example.

For example, the pretreatment unit 20 shown in FIG. 6 may be formed onthe substrate 70 a. In this example, a sample to be analyzed can bepretreated on the electrophoresis chip simultaneously.

(K)

In Embodiments 1 to 3, an example was described in which anelectrophoresis chip of what is called cross type was used in which thesample introduction groove and the electrophoresis groove were crossedwith each other. However, the present invention is not limited to thisexample.

For example, the present invention can be applied to an electrophoresischip of what is called double T type in which two sample introductiongrooves are connected to one electrophoresis groove at differentportions.

INDUSTRIAL APPLICABILITY

The present invention relates to an electrophoresis chip and anelectrophoresis unit having the same to analyze blood components,protein, or nuclei acids.

1. An electrophoresis chip for electrophoresing a sample to be analyzed,comprising: a first sample introduction groove into which the sample isintroduced; a second sample introduction groove into which the sample isintroduced, the second sample introduction groove being formed in aplane different from a plane in which the first sample introductiongroove is formed; a first electrophoresis groove oriented along adirection that intersects with at least one of the first sampleintroduction groove and the second sample introduction groove; a secondelectrophoresis groove oriented along a direction that intersects withat least one of the first sample introduction groove and the secondsample introduction groove, the second electrophoresis groove beingformed in a plane different from a plane in which the firstelectrophoresis groove is formed; and a through hole for connecting thefirst sample introduction groove and the second sample introductiongroove with each other, and for connecting the first electrophoresisgroove and the second electrophoresis groove with each other.
 2. Theelectrophoresis chip as set forth in claim 1, wherein the through holehas a cross section with a length in a direction in which the sample isseparated by electrophoresis is shorter than a length in a direction inwhich the sample is introduced.
 3. The electrophoresis chip as set forthin claim 1, wherein the first sample introduction groove and the firstelectrophoresis groove are formed on one substrate.
 4. Theelectrophoresis chip as set forth in any of claim 1, wherein the secondsample introduction groove and the second electrophoresis groove areformed on one substrate.
 5. The electrophoresis chip as set forth inclaim 3, wherein a pretreatment unit is formed on the substrate forpretreating the sample.
 6. An electrophoresis chip for applying avoltage between ends of a groove into which an electrophoresis liquid isintroduced to electrophorese a sample to be analyzed, comprising: asample introduction groove into which the sample is introduced; and anelectrophoresis groove located along a direction that intersects withthe sample introduction groove, having both ends to which a voltage isapplied to separate the sample by electrophoresis; wherein, theelectrophoresis groove and the sample introduction groove are formed indifferent planes.
 7. The electrophoresis chip as set forth in claim 6,further comprising a through hole located at an intersection between theelectrophoresis groove and the sample introduction groove in a planview, for communicating the electrophoresis groove with the sampleintroduction groove.
 8. The electrophoresis chip as set forth in claim6, further comprising a valve mechanism at an intersection between theelectrophoresis groove and the sample introduction groove in plan view,for preventing a mixture of an electrophoresis liquid introduced intothe electrophoresis groove and a sample introduced into the sampleintroduction groove.
 9. An electrophoresis chip for applying a voltagebetween ends of a groove into which an electrophoresis liquid isintroduced to electrophorese a sample to be analyzed, comprising: asample introduction groove into which the sample is introduced; and anelectrophoresis groove located along a direction that intersects withthe sample introduction groove, having both ends to which a voltage isapplied to separate the sample by electrophoresis; and a valve mechanismlocated at an intersection between the electrophoresis groove and thesample introduction groove, for preventing a mixture of theelectrophoresis liquid and the sample.
 10. The electrophoresis chip asset forth in claim 9, wherein the valve mechanism can be changed into anopen state by using any of mechanical, electrical, and optical means.11. The electrophoresis chip as set forth in claim 10, wherein the valvemechanism can be opened and closed repeatedly.
 12. The electrophoresischip as set forth in claim 10, wherein the valve mechanism includes amembrane that can be opened by light.
 13. The electrophoresis chip asset forth in claim 1, wherein the electrophoresis liquid is an aqueoussolution.
 14. The electrophoresis chip as set forth in claim 6, furthercomprising: a first substrate on which the electrophoresis groove isformed; and a second substrate on which the sample introduction grooveis formed.
 15. The electrophoresis chip as set forth in claim 14,wherein the first substrate and the second substrate are located inparallel with each other.
 16. The electrophoresis chip as set forth inclaim 14, wherein a pretreatment unit is formed on the second substratefor pretreating the sample.
 17. The electrophoresis chip as set forth inclaim 5, wherein the pretreatment unit performs a process of destroyingerythrocytes of blood to take out hemoglobin.
 18. An electrophoresisunit comprising: the electrophoresis chip set forth in claim 1; adetection unit for detecting components contained in the sample that isseparated in the electrophoresis groove; and an analysis unit foranalyzing the components detected by the detection unit.
 19. Theelectrophoresis chip as set forth in claim 6, wherein theelectrophoresis liquid is an aqueous solution.
 20. The electrophoresischip as set forth in claim 9, wherein the electrophoresis liquid is anaqueous solution.
 21. The electrophoresis chip as set forth in claim 9,further comprising: a first substrate on which the electrophoresisgroove is formed; and a second substrate on which the sampleintroduction groove is formed.